The proposed research is concerned with an investigation of the synthesis of influenza virus specific RNA and proteins. Studies of these events are difficult in the intact host cell because of the complexity of replication. The isolation of the viral specific bio-synthetic processes by use of cell-free systems will permit studies on the requirement of the individual processes, the product formed and the role of host cell metabolism in influenza virus directed synthesis. Current studies of this laboratory indicate that a host factor stimulates the rate of influenza RNA transcription catalyzed by the virion carried polymerase. Purification of the virion polymerase and characterization of the factor will permit studies on the mechanism of stimulation. An influenza specific RNA polymerase activity that may represent a transcriptional complex has been isolated from the infected cell. Investigations of the requirements of the virion and cellular polymerase activities and a comparison of the two with respect to the role of host proteins may shed light on the control of the transcriptional process. A study of the synthesis of influenza proteins in cell-free systems will provide information about the site of synthesis of the proteins into translational controls.